View full sizeKaine Horman speaks to the media about his son's disappearance in 2010.Jamie Francis/The Oregonian

Kaine Horman's attorney is expected to ask a Multnomah County judge Monday morning for a further delay in the divorce proceeding with his estranged wife, Terri Moulton Horman.

Kaine Horman had petitioned for a divorce from his wife, shortly after his son, Kyron Horman, disappeared on June 4, 2010 from Skyline School.

The second-grader was last seen at Skyline School after his stepmom, Terri Moulton Horman, drove him to school for a science fair.

While no arrests have been made, investigators have focused intently on Terri Horman.

Kaine Horman had filed for divorce June 28, 2010, two days after investigators informed him that his wife had discussed with a landscaper an alleged murder-for-hire plot to kill him about six months before Kyron's disappearance.

Kaine Horman left their rural Northwest Portland home immediately, but soon after forced his estranged wife out of the home. Kaine returned to the Northwest Portland house, with sole custody of their younger daughter.

In October 2010, Multnomah County Judge Keith Meisenheimer delayed for 90 days the Horman couple's divorce hearing, ruling that Terri Horman faced "substantial legal risk" if it were to proceed while a criminal investigation into Kyron's disappearance continued.

At that time, Kaine Horman's attorney, Laura Rackner, had argued against a delay, concerned the divorce could be delayed indefinitely and that would hurt the children.

In subsequent months, the two sides agreed to further delays in the divorce proceedings.

Kaine Horman also has a restraining order against his wife, which is effective through June 24.

In a related case, a Multnomah County judge in late November granted motions by the district attorney and sheriff to delay Desiree Young's civil lawsuit against Terri Horman until Aug. 1.

Multnomah County Judge Henry Kantor said he was convinced that allowing the civil lawsuit to proceed "could impact an ongoing criminal investigation."

The lawsuit filed by Young, Kyron's mom, alleges that Terri Horman had kidnapped Kyron. Young, in the lawsuit, urges the court to order Terri Horman to bring Kyron back or divulge where his body is located.